Describe the bug

The detection of cannot move X to a subdirectory of itself, X/Y is imperfect, and it is sometime still possible to execute the move, resulting in the directory disappearing.

How to reproduce

korsika in /tmp/foo
➜ mkdir foo/bar-blubb/alt 1 2 3

korsika in /tmp/foo
➜ mv * foo/bar-blubb/alt

korsika in /tmp/foo
➜ ls
╭────────────╮
│ empty list │
╰────────────╯

Expected behavior

Error message.

Configuration

(As obtained from github:NixOS/nixpkgs/3fcada1050e3820241590679838954bacf7d38f8#nushell.)

korsika in /tmp/foo
➜ findmnt -T .
TARGET
  SOURCE    FSTYPE OPTIONS
/ /dev/dm-0 btrfs  rw,relatime,ssd,space_cache=v2,subvolid=5,subvol=/

Additional context

This is not a duplicate of #2612, that's still sound and fixed..